The handling of high-temperature liquids, such as molten steel, requires special materials and techniques. Ladles used for handling molten steel are comprised of an outer metallic shell that is lined with a refractory material. The inner surface of the metallic shell is typically lined with one or more layers of a refractory material, often brick, that can withstand extremely high temperatures and harsh, abrasive conditions. As will be appreciated, the process of laying refractory bricks within a steel ladle is very labor intensive and expensive. In this respect, workers must manually lay courses of bricks along the bottom and sides of the ladle.
Recent developments in forming precast ladle bottoms have eliminated the need for workers to lay bricks on the bottom of the ladle. In this respect, U.S. Pat. Nos. 6,673,306 and 6,787,098, both to Abrino et al., disclose precast ladle bottoms that can be inserted into the bottom of a steel ladle in one piece. While such a structure eliminates the need to brick the bottom of the ladle, it does not eliminate laying bricks along the sides of the ladle. Despite the problems that were solved by the use of precast ladle bottoms, ladle side walls are often still constructed of brick, presenting a similar problem with respect to labor costs and the potential ergonomic issues confronted by the brick layers.
In this respect, the typical method of bricking the side walls around a preformed bottom lining involves lowering a pallet full of brick onto a bottom lining, using a crane. Once the pallet of bricks is within the ladle, laborers descend into the ladle using a ladder and proceed with laying the brick. The laborer begins laying the first course of brick at his feet and must work around the pallet of bricks within the ladle.
Moreover, the first course of bricks is often a starter set of bricks that creates a ramp such that subsequent bricks that form the lining of the side walls spiral up the walls of the ladle. Such starter bricks further require special attention to insure the proper ramp is established by the first course of bricks. Because space is restricted due to the presence of the pallet of bricks within the ladle, laying bricks creates ergonomic problems for the laborers. Even as the height of the brick increases as the side wall is constructed, the repetitive movements of taking bricks from the pallet and placing them into the side walls can cause ergonomic problems.
To date, the only solution to laying brick side walls in steel ladles has been to cast the ladle side wall. To cast a ladle side wall, a form or “mandrel” is placed into the ladle so that a space is defined between the form and the side wall of the ladle. One or more castable materials can be placed or poured between the form and the side wall to create the refractory lining. Casting ladle side walls in this manner requires the fabrication of the form or mandrel and further creates problems with respect to the poured or cast material. In this respect, controlled dry-out procedures are necessary to insure that the cast refractory lining remains intact without steam spalling. In this respect, care must be taken to insure that all water is dried out of the cast refractory lining before use. The creation of steam from residual water can create a dangerous condition when hot liquid steel flows into the ladle during use. Still further, the costs of cast refractory material that can withstand the high temperature and corrosive environment of the steel ladle are typically fairly high. Thus, despite the undesirable working conditions and costs, lining steel ladles with refractory bricks is still a preferred course of action.
The present invention provides a preformed refractory component and side wall structure that mitigate the ergonomic issues confronting laborers in lining a steel ladle with bricks.